The present invention relates to a thin film magnetic head, a substrate for the thin film magnetic head, and a method for fabricating the substrate for the thin film magnetic head.
In recent years, thin film magnetic heads are used for various magnetic recording devices such as hard disk drive (HDD) devices and floppy disk drive (FDD) devices. Such a thin film magnetic head is essentially composed of a substrate, a magnetic shield film deposited on the substrate, and a magnetic element (such as a magnetoresistance (MR) element) and a recording head section formed on the magnetic shield film. The magnetic shield film is made of a soft magnetic material such as Fe--Ni permalloy, Co--Nb--Zr and Co--Fe--B--Si Co-base amorphous materials, and FeAlSi alloy (sendust). As the substrate of the thin film magnetic head, broadly used is a type having an insulating layer made of aluminum oxide deposited on a ceramic base plate made of alumina titanium carbide (AlTiC).
The above thin film magnetic head has a drawback as follows. The adhesion between the AlTiC base plate and the aluminum oxide layer formed thereon is poor, whereby the aluminum oxide layer tends to delaminate from the AlTiC base plate at the interface during the fabrication process and mounting process of the thin film magnetic head, as well as during the actual use thereof. Methods for solving this problem have been proposed, including the method in which an interlayer is provided between the AlTiC base plate and the aluminum oxide layer (see Japanese Patent Publication No. 2-59604) and the method in which the surface of the AlTiC base plate is roughened (see Japanese Laid-Open Patent Publication No. 2-154308). However, there has yet been realized neither a thin film magnetic head substrate of which the AlTiC base plate and the aluminum oxide layer adhere to each other with sufficiently high strength, nor an efficient method for fabricating such a substrate.
A primary object of the present invention is to provide a thin film magnetic head substrate with high reliability where the AlTiC base plate and the aluminum oxide layer adhere to each other with high adhesion strength, and an efficient method for fabricating such a thin film magnetic head substrate.